The invention relates to filter screens, and more particularly to filter screens having screen panels.
Wastewater and water treatment plants utilize filter screens to remove harmful debris from channeled water. The filter screen is typically utilized in the first area to come in contact with the channeled water. In order to protect downstream equipment and processes, the filter screen removes debris before it comes into contact with any downstream equipment.
One type of filter screen includes a grid assembly and a drive system to move and rotate the grid assembly. The drive system includes an endless chain, and a plurality of screen panels that are connected to the chain. The screen panels generally include a frame and filter inserts that are supported by the frame.
The movement of the chain and screen panels result in wear of the chain and its components. Prior art screens do not facilitate inspection of the chain and its components. The prior art designs require that the chain and screen panel assemblies be completely disassembled from the chain and removed from the filter screen for either inspection or replacement of chain components. In the prior art arrangements, when the frames and chains are disassembled, the chain becomes unsupported and clamps are required to hold all the components in place while the inspection or the replacement of chain components takes place.
The filter screens remove debris from the water when the water is channeled from the interior of the grid assembly to the exterior of the grid assembly through the bottom and sides of the grid assembly. Debris commonly becomes trapped on the interior side of the filter screens and must be manually removed to ensure proper operation. Known grid assemblies do not facilitate access to the interior of the grid assembly. These designs require the chain to be separated and the filter screen to be removed to gain access to the interior of the grid assembly for the removal of trapped debris.
The present invention is directed to a filter screen that simplifies inspection and maintenance of the grid assembly by providing pivoting screen panels. The screen panels are coupled to the chain for selective pivoting movement such that the screen panel can be pivoted relative to the chain for repair and/or inspection without completely removing the screen panels from the chain. The screen panels also provide access to the chain components and the interior of the grid assembly while maintaining continuous connection of the chain.
One embodiment of the present invention is directed to a filter screen for use in filtering water. The filter screen includes a frame and a grid assembly that is supported by the frame for movement. The grid assembly includes a continuous unbroken drive chain having a guide link, and a screen panel. The screen panel is coupled to the guide link for selective movement between an operating condition and a maintenance condition. When the screen panel is in the operating condition the screen panel is fixed relative to the guide link for movement with the guide link and for filtering water. In the maintenance condition, the screen panel is pivotable relative to the guide link to permit access to the interior of the filter screen for inspection of chain components.
Another embodiment of the invention is directed to a grid assembly for use in a filter screen to filter water. The grid assembly includes a continuous unbroken drive chain having a guide link, and a screen panel. The screen panel is coupled to the guide link for selective movement between an operating condition and a maintenance condition. When the screen panel is in the operating condition the screen panel is fixed relative to the guide link for movement with the guide link and for filtering water. In the maintenance condition, the screen panel is pivotable relative to the guide link to permit access to the interior of the filter screen for inspection of chain components.
Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims, and drawings.